Core B wiil provide 3 primary funcfions to the Program Project. First, Core B will provide research specimens to the investigators and assist with identificafion, immunostaining and image analysis. Paraffin-embedded sections will be provided from original tumors or tissue microarrays and used to 1) confirm tissue histology using roufine H&E;2) analyze apoptosis using ACINUS, proliferation using MIB-1 detecfion of Ki-67 or BrdU incorporation and androgen receptor using monoclonal antibodies by standard, descriptive immunohistochemistry and quanfitative analysis using visual scoring and/or automated image analysis;and 3) idenfify and quanfify steroid receptor co-regulators, androgen metabolism enzymes, androgen-regulated gene products (PSA, Nkx3.1, a-tubulin, translation elongation factor la, non-neuronal enolase, tomoregulin, thioredoxin reducatase 1, Mxi-1 and human kallikrein 2), general transcripfion factors, growth factors and their receptors and stem cell and angiogenesis biomarkers using immunohistochemistry and image analysis. Second, Core B will be responsible for storage, processing and sectioning of clinical (frozen, archival and TMAs) and prostate cancer xenograft (CWR22) research specimens. Core personnel will procure, process and store clinical specimens of castrafion-recurrent prostate cancer obtained from men with advanced prostate cancer who present with urinary retention due to local recurrence. Research specimens will be used to construct tissue microarrays or laser capture microdissected for biochemical measurements of fissue androgens. Lastly, Core B will provide expert biostatistical (Dr. Wilding) and genitourinary pathological service (Dr. Alexiev) to the Program Project. Drs. Mohler and Smith will co-direct the facility and supervise the acfivifies of individuals who already possess high levels of expertise and currently perform these funcfions for the Program Project. Drs. Wilding and Alexiev will lead the efforts to integrate biostatistical and pathological expertise into Core B and the 3 projects. The high level of funcfion of Core B is demonstrated best by Core B's publicafion of 8 methods papers. Core B continues to develop new methods for more accurate measurement of protein expression (4 publicafions) and remains a leader in the use of TMAs for CaP research (2 publications). Core B has performed services that have resulted in manuscripts published, in press and submitted for Project 1 (20), Project 2 (8) and Project 3 (8). Core B also facilitates interaction among the Projects;12 of 23 publications involved more than 1 Project.